Field
The present disclosure relates to an imprint apparatus for forming a pattern on a substrate by contacting an imprint material on the substrate with a mold, an imprinting mold, and a method of manufacturing an article.
Description of the Related Art
Demands for miniaturization of semiconductor devices are increasing and attention is focused on microfabrication techniques as well as known photolithography techniques. A microfabrication technique is to form a fine pattern on a substrate by contacting an imprint material on the substrate with a mold having a micro-relief pattern. This technique, called an “imprinting technique”, enables a fine structure on the order of a few nanometers to be formed on a substrate. Examples of imprinting techniques includes a photo-curing method. According to the photo-curing method, first, a shot area (imprint area) of a substrate (wafer) is coated with an imprint material, such as an ultraviolet (UV) curable resin or a photo-curable resin. Then, the imprint material is brought into contact with a mold such that they are pressed against each other. The imprint material in contact with the mold is irradiated with light (UV light), thus curing the imprint material. Lastly, the mold is separated or released from the cured imprint material, so that a pattern is formed on the substrate.
An imprint apparatus using the above-described technique typically includes a magnification correction mechanism to correct a pattern magnification error generated during a semiconductor process. The magnification correction mechanism includes a contact portion to contact with a mold and a sensor for controlling an amount of driving the contact portion. A plurality of magnification correction mechanisms are arranged so as to surround the mold. In this case, each magnification correction mechanism applies an external force to the mold to deform the mold, thus correcting the shape of a pattern formed in the mold. At this time, the pattern shape affects overlay precision with a pattern previously formed on a substrate. Accordingly, a highly accurate correction on the order of a few nanometers is required for pattern miniaturization. For example, PCT Japanese Translation Patent Publication No. 2008-504141 discloses a correction apparatus which corrects a magnification by applying a compressive force to a side surface of a mold. Japanese Patent Laid-Open No. 2009-141328 discloses an imprint apparatus including actuators arranged between each side surface of a mold and a support structure and force sensors each of which is disposed between the actuator and the support structure. Each actuator applies a compressive force to the side surface of the mold and each force sensor controls the amount of driving the actuator. Japanese Patent Laid-Open No. 2012-23092 discloses an imprint apparatus in which a position to be detected by a displacement sensor for detecting a position of a side surface of a mold is located in a plane in which a contact portion comes into contact with the mold.
The contact portions of the magnification correction mechanisms are in contact with the mold. The contact portions are pressed parallel to a pattern face of the mold, thus deforming the mold in a direction parallel to the pattern face. Each side surface of the mold is not necessarily perpendicular to the pattern face because of a manufacturing error or the like. Accordingly, a state of contact between each contact portion and the mold varies depending on position. Unfortunately, forces are applied to the mold in a Z direction (perpendicular to the pattern face of the mold) such that the magnitude and direction of the force vary from position to position. The forces are applied to the mold in the Z direction in this manner, so that the mold is deformed into a complex shape and the accuracy of correcting the pattern shape is reduced. This may lead to lower overlay precision with the pattern on the substrate.